1. Field of Invention
This invention pertains generally to inertial rate sensors and, more particularly, to an inertial rate sensor and method with improved tuning fork drive.
2. Related Art
Inertial rate sensors are used in a wide variety of applications including aircraft navigation, the guidance of missiles and spacecraft, and automotive stability control systems. In many of these applications, safety is critical, and measures must be taken to guard against failures of the sensor.
It is in general an object of the invention to provide a new and improved inertial rate sensor and method.
Another object of the invention is to provide an inertial rate sensor and method with improved tuning fork drive.
These and other objects are achieved in accordance with the invention by providing an inertial rate sensor and method in which a drive signal consisting initially of a square wave and thereafter a sine wave is applied to a vibratory rate sensing element, a pickup circuit is coupled to the rate sensing element for providing an output signal corresponding to movement of the rate sensing element, the magnitude of the drive signals is adjusted to set a scale factor which determines the sensitivity to movement of the rate sensing element, and a signal in the drive circuit is monitored to detect a failure.